During a chance meeting at a Starbucks on a quiet Sunday morning in Austin, Texas, architect Winn Wittman agreed to help transform businessman Milton Verret’s staid mid-1990s McMansion into a lively and contemporary haven. Completed this year, the reenergized five-bedroom, 10,500-square-foot lakeside house—Verret’s primary residence—now incorporates automated systems for both lighting and audiovisual entertainment and has two climate-controlled garages for the owner’s car collection (which includes a 2010 Lamborghini Murciélago LP670-4 SuperVeloce, a 2010 Ferrari 458 Italia, a 1967 Chevy Nova, and a 1956 Cadillac convertible). Wittman added playful, unifying elements during the two-year renovation, including powder-coated-steel screens with decorative cutouts that keep the house cool, and an uplit motor court of concrete strips that, says Verret, “looks like a runway.”

Seeing the Light | To maximize light in the double-height living room, Wittman added floor-to-ceiling glass windows and several Zeppelin lamps by Dutch designer Marcel Wanders. The lamps reflect off of a silver-leaf ceiling, illuminating some of the detail that went into this once disorderly space. “It was a mess,” says Wittman of the room’s previous incarnation. “There was a piano-shaped swimming pool right in the middle, and everything leaked.” The architect and homeowner made the space more elegant with furnishings they chose on buying trips to New York, Miami, and Los Angeles, such as the sofas and coffee table from Minotti and the chair from Swiss manufacturer de Sede. Wittman also incorporated a whole-home audio system from Bang & Olufsen. “The living room is fantastic for just sitting, relaxing, and watching the sailboats out in the lake,” says Verret, whose four grown children and two grandchildren often come to the house for long weekends.

In the second-floor landing, Wittman installed droplet-shaped lights from Leucos that are wired with fiber-optic filaments. The filaments change color at the touch of Verret’s iPad, from which he can control all of the home’s lighting. Wittman embellished the existing porthole windows by placing the decorative steel screen outside; the 1970s Lucite-and-metal rocking chair by Charles Hollis Jones echoes their round shapes. He also transformed a flimsy spiral stair into a curvilinear, modern version that evokes the lines of the staircase in Le Corbusier’s Villa Savoye outside Paris. The circular leitmotif continues in the powder room (bottom), which features an illuminated sink and mirror, both purchased at shops in Miami, and a sculptural bowl by Dale Chihuly. “Milton really appreciates unusual pieces,” says Wittman.

Made to Order | Although Verret does not spend much time in the kitchen (left), he says it is a natural gathering place when family and friends visit. “I don’t do a lot of cooking,” he says, “but I do like to hang out in the dining room.” Wittman worked with builder Gary Robinson to reconceptualize the kitchen, as well as the rest of the house, and bring about a better sense of order. They added an island sheathed in CaesarStone quartz—the same material used in the floor—and created a generous pass-through and walkways to the dining space. There, a Mercury chandelier from Artemide hovers above a contemporary aluminum-and-glass dining table; an array of chairs, some designed by Philippe Starck, surround the table. “For the first time,” says Witt­man, “the kitchen and dining room are completely congruous.” And both rooms, like the other main areas of the home, are located on the second floor, with sweeping views of the lake.

Suite Harmony | The third floor contains the master bath (left) and the master bedroom, which affords commanding water vistas. “It’s nice to wake up to,” says Ver­ret. A separate shower and soaking tub from Kos grace the bathroom, while an outdoor shower sits just beyond the bedroom’s sliding glass doors. On the bed is a guitar Bo Diddley played onstage. (Both Verret and Wittman are musicians, and they sometimes have jam sessions in a second bedroom at the house.) Holding all of the master suite’s audiovisual equipment is a cabinet made to resemble a flight case, by Diesel. Italian accents include a chair and ottoman from Moroso, a leather-framed bed by Molteni&C, and a Fos­carini floor lamp. “We wanted to use more whimsical pieces for this project and not just the straightforward [Ludwig] Mies van der Rohe classics,” says Wittman.

Water Ways | Cascading, low-slung terraces with transparent railings built to withstand hurricane-force winds unify the rear facade. The negative-edge swimming pool, which Wittman says “appears to be rising out of the lake,” was modeled after the Delano hotel’s in Miami—a favorite of Verret’s. The home’s pool, with its hot tub and cold plunge situated at two corners, is accessible via the breezeway that bisects the house’s first floor. In warm weather, Verret and his guests take a new private tram from the pool terrace down the hillside to the dock, where he keeps his watercraft. “We spend a lot of time in the pool or hanging out on the decks—it’s a fun place to be,” says Verret. “It just doesn’t get any better than those views.”

The views add to the resortlike ambience at Verret’s home, which, says the architect, has a calming effect on its owner. “After Milton had lived in the house for a little while, he gave us the greatest compliment,” explains Wittman. “He said that every time he gets home, his blood pressure lowers by about 20 degrees.”